Hierarchical PTFE–PP/SiO 2 Composite Textile for Efficient Dual-Mode Radiative Thermal Management

As sustainable and eco-friendly passive thermal management techniques, passive radiative cooling and solar heating have attracted significant attention for applications in green energy and energy-saving systems. However, conventional thermal management strategies face significant challenges, such as static operation and limited functional adaptability, making them unsuitable for applications that demand dynamic cooling and heating. Herein, a hierarchical sandwich-structured composite textile was fabricated by depositing SiO2 nanoparticles onto porous polypropylene (PP) fibers via ultrasound-assisted self-assembly, followed by laminating a polytetrafluoroethylene (PTFE) film and conductive fabric on opposite sides. The asymmetric design enables dual-mode thermal regulation-radiative cooling or solar heating-by simply flipping the textile. The cooling side exhibits a high solar reflectivity of 96.3% and a high mid-infrared (MIR, 8–13 μm) emissivity of 95.8%, resulting in a subambient cooling effect of 7.5 °C during daytime. In contrast, the heating side, with a low solar reflectivity of 5.7% and low infrared emissivity of 31.2%, achieves a maximum heating effect of 47.6 °C under direct sunlight. Moreover, the textile exhibits excellent thermal stability, enhanced mechanical strength, and favorable water vapor permeability, making it suitable for multifunctional thermal management applications. The proposed strategy shows potential for contributing to thermal management in areas such as aerospace, building, and wearable applications.